This invention relates to heating apparatus in general and more particularly to an improved solar heating apparatus.
The need for more and better sources of fresh water for various uses throughout the world has received much attention of late. It is recognized that our present water supplies will be insufficient to meet future needs. In addition, attempts to desalinize sea water near desert areas for use in irrigation and other purposes has been recognized. The ability to convert sea water to fresh water efficiently and cheaply can make available large areas of land for use in growing crops, which areas formerly were arid and useless.
Various attempts in using solar energy to distill water have been made. In each case, the disclosed apparatus has been considerably complex and costly. For example, in U.S. Pat. No. 2,975,107 a system is disclosed in which the salt water is boiled in a vessel which has heat from the sun directed on its base by means of a reflector. Clearly the vessels involved along with the necessary reflectors result in a large expense.
In another type of device disclosed in U.S. Pat. No. 3,351,536 designed particularly for emergency use at sea, a solar dome which fits over a box-like container, the dome containing lenses, is provided. The necessity to form a lensed dome and the small size of a unit of this type makes it impracticable for converting larger quantities of salt water. In an arrangement disclosed in U.S. Pat. No. 3,775,527 a transparent dome condenses solar energy and heats sea water in a container there beneath. A continuous channel for conveying vaporized liquid to a condenser tank is contained along the periphery of the dome. This too is a relatively complex system. Finally in U.S. Pat. No. 3,616,270 pressure vessel plates with tortuous water conduits therein for absorbing the sun's energy are employed for conversion purposes. Naturally, such a large area of metal plates, if it is to be made of a highly conductive material such as copper will be extremely expensive.
Thus, although it has been recognized that solar energy can be used for converting salt water into fresh water in a desalinization process, the apparatus used in the prior art has been relatively complex and expensive to build. Thus, the need for an improved type of apparatus which is simple and inexpensive becomes evident.
Attention has also been directed to the use of solar energy for heating habitable structures. Such use of solar energy has become particularly important in view of the recent energy crisis. Thus, in addition to the need for improved apparatus for desolarization, there is also a need for arrangements which permit using solar heat for heating habitable spaces.